// mcaptcha.js
export class Mcaptcha {
	constructor(options) {
		this.options = options;
		this.fontSize = options.height * 3 / 6;
		this.init();
		this.refresh();
	}
	init() {
		this.ctx = uni.createCanvasContext(this.options.el, this.options.instance);
		this.ctx.setTextBaseline("middle");
		this.ctx.setFillStyle(this.randomColor(180, 240));
	}
	refresh() {
		var code = '';
		var txtArr = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's',
			't', 'u', 'v', 'w', 'x', 'y', 'z', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
			'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 0, 1, 2, 3, 4, 5, 6, 7, 8, 9
		]
		for (var i = 0; i < 4; i++) {
			code += txtArr[this.randomNum(0, txtArr.length)];
		}
		this.options.createCodeImg = code;
		let arr = (code + '').split('');
		if (arr.length === 0) {
			arr = ['e', 'r', 'r', 'o', 'r'];
		};
		let offsetLeft = this.options.width * 0.6 / (arr.length - 1);
		let marginLeft = this.options.width * 0.2;
		arr.forEach((item, index) => {
			this.ctx.setFillStyle(this.randomColor(0, 180));
			let size = this.randomNum(24, this.fontSize);
			this.ctx.setFontSize(size);
			let dis = offsetLeft * index + marginLeft - size * 0.3;
			let deg = this.randomNum(-30, 30);
			this.ctx.translate(dis, this.options.height * 0.5);
			this.ctx.rotate(deg * Math.PI / 180);
			this.ctx.fillText(item, 0, 0);
			this.ctx.rotate(-deg * Math.PI / 180);
			this.ctx.translate(-dis, -this.options.height * 0.5);
		})
		for (var i = 0; i < 4; i++) {
			this.ctx.strokeStyle = this.randomColor(40, 180);
			this.ctx.beginPath();
			this.ctx.moveTo(this.randomNum(0, this.options.width), this.randomNum(0, this.options.height));
			this.ctx.lineTo(this.randomNum(0, this.options.width), this.randomNum(0, this.options.height));
			this.ctx.stroke();
		}
		for (var i = 0; i < this.options.width / 4; i++) {
			this.ctx.fillStyle = this.randomColor(0, 255);
			this.ctx.beginPath();
			this.ctx.arc(this.randomNum(0, this.options.width), this.randomNum(0, this.options.height), 1, 0, 2 *
				Math.PI);
			this.ctx.fill();
		}
		this.ctx.draw();
	}
	validate(code) {
		var code = code.toLowerCase();
		var v_code = this.options.createCodeImg.toLowerCase();
		console.log(code)
		console.log(v_code.substring(v_code.length - 4))
		if (code == v_code.substring(v_code.length - 4)) {
			return true;
		} else {
			return false;
		}
	}
	randomNum(min, max) {
		return Math.floor(Math.random() * (max - min) + min);
	}
	randomColor(min, max) {
		let r = this.randomNum(min, max);
		let g = this.randomNum(min, max);
		let b = this.randomNum(min, max);
		return "rgb(" + r + "," + g + "," + b + ")";
	}
}